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    <title>Document</title>
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    <script>
        function Person (n, a) {
            this.name = n;
            this.age = a;
            this.say = function() {
                console.log('hello');
            }
        }
        let p1 = new Person('Tom', 18);
        console.log(p1.age);
        p1.say()
    </script>
</body>
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